The present invention relates generally to fluid control valves and, more particularly, to a flow switchable check valve for downhole tools.
Various procedures have been developed and utilized to increase the flow of hydrocarbons from hydrocarbon-containing subterranean formations penetrated by wellbores. For example, a commonly used production stimulation technique involves creating and extending fractures in the subterranean formation to provide flow channels therein through which hydrocarbons flow from the formation to the wellbore. The fractures are created by introducing a fracturing fluid into the formation at a flow rate which exerts a sufficient pressure on the formation to create and extend fractures therein. Solid fracture proppant materials, such as sand, are commonly suspended in the fracturing fluid so that upon introducing the fracturing fluid into the formation and creating and extending fractures therein, the proppant material is carried into the fractures and deposited therein, whereby the fractures are prevented from closing due to subterranean forces when the introduction of the fracturing fluid has ceased.
In such formation fracturing and other production stimulation procedures, hydraulic fracturing tools and other production enhancement and completion tools often use fluid circulation to operate the downhole tools to obtain the desired result. The control of fluid circulation paths are achieved in many instances by check valves, such as ball valves that open when fluid flows in one direction and close when fluid flows in the opposite direction.